<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>box</title>
    <style>
        /*
        .box {
            border: 1px solid black;
            width: 300px;
            height: 200px;
            padding: 10px 20px 30px 40px;
            margin: 40px 30px 20px 10px;
        }
        */
        .box {
            border-top: 1px solid black;
            border-right: 2px dashed blue;
            border-bottom: 2px dotted green;
            width: 300px;
            height: 200px;
            padding: 20px;  /*四个方向的内边距全部是20*/
            margin: 10px 20px;  /*上下10，左右20px*/
            background-color: silver;
        }
        body {
            /*background-image: url("http://img.sj33.cn/uploads/allimg/200808/20080807150441542.png");*/
            /*background-repeat: repeat-x;*/
            /*background-repeat: repeat-y;*/
            /*background-repeat: no-repeat;*/
        }
        .c1 {
            font-family: Fantasy;  /*字体*/
            font-size: 20px;   /*字号*/
            font-weight: bold;   /*加粗*/
            font-style: italic;  /*倾斜*/
            font-variant: small-caps;  /*小型大写字母*/
        }
        .c2 {
            font-family: Serif;
            text-align: center;  /*对齐方式*/
            text-decoration: underline;   /*下划线*/
            color: green;  /*前景色*/
        }
        .c3 {
            font-family: Monospace;
        }
        .c4 {
            height: 60px;
            border: 1px dotted black;
            text-align: center;
            line-height: 60px;
            width: 1000px;
            margin: 0 auto;
        }
    </style>
</head>
<body>
<div class="c4">字体abcdABCD</div>
<div class="c1">字体abcdABCD</div>
<div class="c2">字体abcdABCD</div>
<div class="c3">字体abcdABCD</div>
<div class="box">
    这是一个框模型
</div>
</body>
</html>